1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Real Time Clock driver for Marvell 88PM860x PMIC 4 * 5 * Copyright (c) 2010 Marvell International Ltd. 6 * Author: Haojian Zhuang <haojian.zhuang@marvell.com> 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/of.h> 12 #include <linux/platform_device.h> 13 #include <linux/slab.h> 14 #include <linux/mutex.h> 15 #include <linux/rtc.h> 16 #include <linux/delay.h> 17 #include <linux/mfd/core.h> 18 #include <linux/mfd/88pm860x.h> 19 20 #define VRTC_CALIBRATION 21 22 struct pm860x_rtc_info { 23 struct pm860x_chip *chip; 24 struct i2c_client *i2c; 25 struct rtc_device *rtc_dev; 26 struct device *dev; 27 struct delayed_work calib_work; 28 29 int irq; 30 int vrtc; 31 int (*sync)(unsigned int ticks); 32 }; 33 34 #define REG_VRTC_MEAS1 0x7D 35 36 #define REG0_ADDR 0xB0 37 #define REG1_ADDR 0xB2 38 #define REG2_ADDR 0xB4 39 #define REG3_ADDR 0xB6 40 41 #define REG0_DATA 0xB1 42 #define REG1_DATA 0xB3 43 #define REG2_DATA 0xB5 44 #define REG3_DATA 0xB7 45 46 /* bit definitions of Measurement Enable Register 2 (0x51) */ 47 #define MEAS2_VRTC (1 << 0) 48 49 /* bit definitions of RTC Register 1 (0xA0) */ 50 #define ALARM_EN (1 << 3) 51 #define ALARM_WAKEUP (1 << 4) 52 #define ALARM (1 << 5) 53 #define RTC1_USE_XO (1 << 7) 54 55 #define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */ 56 57 static irqreturn_t rtc_update_handler(int irq, void *data) 58 { 59 struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data; 60 int mask; 61 62 mask = ALARM | ALARM_WAKEUP; 63 pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask); 64 rtc_update_irq(info->rtc_dev, 1, RTC_AF); 65 return IRQ_HANDLED; 66 } 67 68 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 69 { 70 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 71 72 if (enabled) 73 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN); 74 else 75 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 76 return 0; 77 } 78 79 /* 80 * Calculate the next alarm time given the requested alarm time mask 81 * and the current time. 82 */ 83 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, 84 struct rtc_time *alrm) 85 { 86 unsigned long next_time; 87 unsigned long now_time; 88 89 next->tm_year = now->tm_year; 90 next->tm_mon = now->tm_mon; 91 next->tm_mday = now->tm_mday; 92 next->tm_hour = alrm->tm_hour; 93 next->tm_min = alrm->tm_min; 94 next->tm_sec = alrm->tm_sec; 95 96 rtc_tm_to_time(now, &now_time); 97 rtc_tm_to_time(next, &next_time); 98 99 if (next_time < now_time) { 100 /* Advance one day */ 101 next_time += 60 * 60 * 24; 102 rtc_time_to_tm(next_time, next); 103 } 104 } 105 106 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm) 107 { 108 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 109 unsigned char buf[8]; 110 unsigned long ticks, base, data; 111 112 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 113 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 114 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 115 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 116 (buf[5] << 8) | buf[7]; 117 118 /* load 32-bit read-only counter */ 119 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 120 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 121 (buf[1] << 8) | buf[0]; 122 ticks = base + data; 123 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 124 base, data, ticks); 125 126 rtc_time_to_tm(ticks, tm); 127 128 return 0; 129 } 130 131 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm) 132 { 133 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 134 unsigned char buf[4]; 135 unsigned long ticks, base, data; 136 137 if (tm->tm_year > 206) { 138 dev_dbg(info->dev, "Set time %d out of range. " 139 "Please set time between 1970 to 2106.\n", 140 1900 + tm->tm_year); 141 return -EINVAL; 142 } 143 rtc_tm_to_time(tm, &ticks); 144 145 /* load 32-bit read-only counter */ 146 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 147 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 148 (buf[1] << 8) | buf[0]; 149 base = ticks - data; 150 dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 151 base, data, ticks); 152 153 pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF); 154 pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF); 155 pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF); 156 pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF); 157 158 if (info->sync) 159 info->sync(ticks); 160 return 0; 161 } 162 163 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 164 { 165 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 166 unsigned char buf[8]; 167 unsigned long ticks, base, data; 168 int ret; 169 170 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 171 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 172 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 173 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 174 (buf[5] << 8) | buf[7]; 175 176 pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 177 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 178 (buf[1] << 8) | buf[0]; 179 ticks = base + data; 180 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 181 base, data, ticks); 182 183 rtc_time_to_tm(ticks, &alrm->time); 184 ret = pm860x_reg_read(info->i2c, PM8607_RTC1); 185 alrm->enabled = (ret & ALARM_EN) ? 1 : 0; 186 alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0; 187 return 0; 188 } 189 190 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 191 { 192 struct pm860x_rtc_info *info = dev_get_drvdata(dev); 193 struct rtc_time now_tm, alarm_tm; 194 unsigned long ticks, base, data; 195 unsigned char buf[8]; 196 int mask; 197 198 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0); 199 200 pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf); 201 dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1], 202 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]); 203 base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) | 204 (buf[5] << 8) | buf[7]; 205 206 /* load 32-bit read-only counter */ 207 pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf); 208 data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) | 209 (buf[1] << 8) | buf[0]; 210 ticks = base + data; 211 dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n", 212 base, data, ticks); 213 214 rtc_time_to_tm(ticks, &now_tm); 215 rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time); 216 /* get new ticks for alarm in 24 hours */ 217 rtc_tm_to_time(&alarm_tm, &ticks); 218 data = ticks - base; 219 220 buf[0] = data & 0xff; 221 buf[1] = (data >> 8) & 0xff; 222 buf[2] = (data >> 16) & 0xff; 223 buf[3] = (data >> 24) & 0xff; 224 pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf); 225 if (alrm->enabled) { 226 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 227 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask); 228 } else { 229 mask = ALARM | ALARM_WAKEUP | ALARM_EN; 230 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, 231 ALARM | ALARM_WAKEUP); 232 } 233 return 0; 234 } 235 236 static const struct rtc_class_ops pm860x_rtc_ops = { 237 .read_time = pm860x_rtc_read_time, 238 .set_time = pm860x_rtc_set_time, 239 .read_alarm = pm860x_rtc_read_alarm, 240 .set_alarm = pm860x_rtc_set_alarm, 241 .alarm_irq_enable = pm860x_rtc_alarm_irq_enable, 242 }; 243 244 #ifdef VRTC_CALIBRATION 245 static void calibrate_vrtc_work(struct work_struct *work) 246 { 247 struct pm860x_rtc_info *info = container_of(work, 248 struct pm860x_rtc_info, calib_work.work); 249 unsigned char buf[2]; 250 unsigned int sum, data, mean, vrtc_set; 251 int i; 252 253 for (i = 0, sum = 0; i < 16; i++) { 254 msleep(100); 255 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf); 256 data = (buf[0] << 4) | buf[1]; 257 data = (data * 5400) >> 12; /* convert to mv */ 258 sum += data; 259 } 260 mean = sum >> 4; 261 vrtc_set = 2700 + (info->vrtc & 0x3) * 200; 262 dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set); 263 264 sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1); 265 data = sum & 0x3; 266 if ((mean + 200) < vrtc_set) { 267 /* try higher voltage */ 268 if (++data == 4) 269 goto out; 270 data = (sum & 0xf8) | (data & 0x3); 271 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 272 } else if ((mean - 200) > vrtc_set) { 273 /* try lower voltage */ 274 if (data-- == 0) 275 goto out; 276 data = (sum & 0xf8) | (data & 0x3); 277 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data); 278 } else 279 goto out; 280 dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data); 281 /* trigger next calibration since VRTC is updated */ 282 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 283 return; 284 out: 285 /* disable measurement */ 286 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 287 dev_dbg(info->dev, "finish VRTC calibration\n"); 288 return; 289 } 290 #endif 291 292 #ifdef CONFIG_OF 293 static int pm860x_rtc_dt_init(struct platform_device *pdev, 294 struct pm860x_rtc_info *info) 295 { 296 struct device_node *np = pdev->dev.parent->of_node; 297 int ret; 298 if (!np) 299 return -ENODEV; 300 np = of_get_child_by_name(np, "rtc"); 301 if (!np) { 302 dev_err(&pdev->dev, "failed to find rtc node\n"); 303 return -ENODEV; 304 } 305 ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc); 306 if (ret) 307 info->vrtc = 0; 308 of_node_put(np); 309 return 0; 310 } 311 #else 312 #define pm860x_rtc_dt_init(x, y) (-1) 313 #endif 314 315 static int pm860x_rtc_probe(struct platform_device *pdev) 316 { 317 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 318 struct pm860x_rtc_pdata *pdata = NULL; 319 struct pm860x_rtc_info *info; 320 struct rtc_time tm; 321 unsigned long ticks = 0; 322 int ret; 323 324 pdata = dev_get_platdata(&pdev->dev); 325 326 info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info), 327 GFP_KERNEL); 328 if (!info) 329 return -ENOMEM; 330 info->irq = platform_get_irq(pdev, 0); 331 if (info->irq < 0) { 332 dev_err(&pdev->dev, "No IRQ resource!\n"); 333 return info->irq; 334 } 335 336 info->chip = chip; 337 info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion; 338 info->dev = &pdev->dev; 339 dev_set_drvdata(&pdev->dev, info); 340 341 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 342 rtc_update_handler, IRQF_ONESHOT, "rtc", 343 info); 344 if (ret < 0) { 345 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", 346 info->irq, ret); 347 return ret; 348 } 349 350 /* set addresses of 32-bit base value for RTC time */ 351 pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA); 352 pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA); 353 pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA); 354 pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA); 355 356 ret = pm860x_rtc_read_time(&pdev->dev, &tm); 357 if (ret < 0) { 358 dev_err(&pdev->dev, "Failed to read initial time.\n"); 359 return ret; 360 } 361 if ((tm.tm_year < 70) || (tm.tm_year > 138)) { 362 tm.tm_year = 70; 363 tm.tm_mon = 0; 364 tm.tm_mday = 1; 365 tm.tm_hour = 0; 366 tm.tm_min = 0; 367 tm.tm_sec = 0; 368 ret = pm860x_rtc_set_time(&pdev->dev, &tm); 369 if (ret < 0) { 370 dev_err(&pdev->dev, "Failed to set initial time.\n"); 371 return ret; 372 } 373 } 374 rtc_tm_to_time(&tm, &ticks); 375 if (pm860x_rtc_dt_init(pdev, info)) { 376 if (pdata && pdata->sync) { 377 pdata->sync(ticks); 378 info->sync = pdata->sync; 379 } 380 } 381 382 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc", 383 &pm860x_rtc_ops, THIS_MODULE); 384 ret = PTR_ERR(info->rtc_dev); 385 if (IS_ERR(info->rtc_dev)) { 386 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 387 return ret; 388 } 389 390 /* 391 * enable internal XO instead of internal 3.25MHz clock since it can 392 * free running in PMIC power-down state. 393 */ 394 pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO); 395 396 #ifdef VRTC_CALIBRATION 397 /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */ 398 if (pm860x_rtc_dt_init(pdev, info)) { 399 if (pdata && pdata->vrtc) 400 info->vrtc = pdata->vrtc & 0x3; 401 else 402 info->vrtc = 1; 403 } 404 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC); 405 406 /* calibrate VRTC */ 407 INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work); 408 schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL); 409 #endif /* VRTC_CALIBRATION */ 410 411 device_init_wakeup(&pdev->dev, 1); 412 413 return 0; 414 } 415 416 static int pm860x_rtc_remove(struct platform_device *pdev) 417 { 418 struct pm860x_rtc_info *info = platform_get_drvdata(pdev); 419 420 #ifdef VRTC_CALIBRATION 421 cancel_delayed_work_sync(&info->calib_work); 422 /* disable measurement */ 423 pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0); 424 #endif /* VRTC_CALIBRATION */ 425 426 return 0; 427 } 428 429 #ifdef CONFIG_PM_SLEEP 430 static int pm860x_rtc_suspend(struct device *dev) 431 { 432 struct platform_device *pdev = to_platform_device(dev); 433 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 434 435 if (device_may_wakeup(dev)) 436 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC; 437 return 0; 438 } 439 static int pm860x_rtc_resume(struct device *dev) 440 { 441 struct platform_device *pdev = to_platform_device(dev); 442 struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent); 443 444 if (device_may_wakeup(dev)) 445 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC); 446 return 0; 447 } 448 #endif 449 450 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume); 451 452 static struct platform_driver pm860x_rtc_driver = { 453 .driver = { 454 .name = "88pm860x-rtc", 455 .pm = &pm860x_rtc_pm_ops, 456 }, 457 .probe = pm860x_rtc_probe, 458 .remove = pm860x_rtc_remove, 459 }; 460 461 module_platform_driver(pm860x_rtc_driver); 462 463 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver"); 464 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 465 MODULE_LICENSE("GPL"); 466